Democrats have failed to field a U.S. Senate candidate in as many races since 2000 as they did from 1930 through 1999 (eight)

Democrats are not having the easiest time getting their candidates of choice in vulnerable U.S. Senate races in 2014.

After a failed recruitment of Stephanie Herseth Sandlin in South Dakota, the wheels now seem to be coming off in Montana where the party hopes to hold retiring Max Baucus' seat.

A surprise announcement last weekend by former two-term Governor Brian Schweitzer that he would not enter the race was followed up by news that Montana Auditor Monica Lindeen was also not seeking a Senate seat in 2014.

While Democrats will eventually land a candidate in Montana - though not necessarily a candidate who can win - the party has found greater difficulty in filling the ballot in less competitive states in recent cycles including a first ever failed attempt to run a candidate in South Dakota in 2010 against John Thune.

Overall, a major party candidate has not appeared on the U.S. Senate general or special election ballot in 142 of 1,825 races since the first direct election over a century ago, or 7.8 percent - 117 without Republicans and 25 without Democrats, according to a Smart Politics analysis of election data.

The vast majority of these instances involved races in the deep South from the 1910s to the 1950s, where there was essentially one-party rule for decades and the Democratic primary frequently determined the winner of the seat.

Louisiana leads the way with 20 such contests without a Republican on the ballot since 1913, followed by Georgia with 19, Mississippi with 17, South Carolina with 13, Arkansas with 12, Virginia with 11, Alabama with 10, and Florida with seven.

That accounts for 109 of the 117 races without a GOPer in the direct vote era, with the remaining eight occurring in North Carolina (1948, 1954 - twice), Hawaii (1974), Massachusetts (2002), Tennessee (1934), Texas (1952), and West Virginia (1976).

And as for the 25 races without a Democrat?

No-shows have been on the rise for the Democratic Party over the last decade.

Since 2000, Democrats have been on the short end in eight of the 10 U.S. Senate races in which only one major party candidate was on the ballot: in Arizona (2000, against Jon Kyl), Kansas (2002, Pat Roberts), Indiana (2006, Dick Lugar), Mississippi (2002, Thad Cochran), South Dakota (2010, John Thune), Vermont (2006, 2012, Bernie Sanders), and Virginia (2002, John Warner).

(Note: Sanders, Vermont's victorious independent candidate during those two cycles, does caucus with the Democrats).

As a result, in just 13 years, Democrats have failed to field a candidate in as many U.S. Senate races - eight - as they did during the preceding 70-year period from the 1930s through the 1990s.

During that seven-decade stretch, Democratic nominees were absent from the ballot:

· Three times in the 1930s: California (1934), Minnesota (1936 special and general)· Once in the 1940s: California (1940)· Once in the 1950s: California (1952)· Once in the 1960s: Vermont (1968)· Twice in the 1990s: Mississippi (1990), Virginia (1990)

Minnesota leads the way with the largest number of U.S. Senate contests without a Democratic candidate with four - most during the rise in power of the state's Farmer-Labor Party: in 1918, 1928, 1936, and 1936 (special).

California (1934, 1940, 1952) and Vermont (1968, 2006, 2012) are next with three each.

Republicans, meanwhile, have not fielded a candidate in only two elections since 2000 - in Massachusetts (2002, versus John Kerry) and Arkansas (2008, Mark Pryor).

Since 1980, the only other two races in which there was no Republican candidate on the ballot took place in Arkansas (1990, against David Pryor) and Georgia (1990, Sam Nunn).

A total of 24 states have fielded a major party candidate in every direct vote U.S. Senate election in state history: Alaska, Colorado, Connecticut, Delaware, Idaho, Illinois, Kentucky, Maine, Maryland, Michigan, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, Ohio, Oklahoma, Rhode Island, Utah, Washington, and Wyoming.

Republican-dominated states to watch and see if the Democrats run a candidate in 2014 include Alabama, Idaho, Kansas, Mississippi, Nebraska, Texas, and Wyoming.

A recent Smart Politics report examined state-by-state trends in fielding both Democrats and Republicans in U.S. House races and found Indiana, New Hampshire, Minnesota, Idaho, and Montana have the longest consecutive streaks.

January's preliminary Bureau of Labor Statistics numbers show Minnesota's unemployment rate of 3.7 percent was once again lower than Wisconsin's 5.0 percent. That marks the 73rd consecutive month in which Minnesota has boasted a lower jobless rate than its neighbor to the east dating back to January 2009 including each of the last 67 months by at least one point. The Gopher State has now edged Wisconsin in the employment border battle for 204 of the last 216 months dating back to February 1997. Wisconsin only managed a lower unemployment rate than Minnesota for the 12 months of 2008 during this 18-year span.

For each of the last 24 presidential elections since 1920, North and South Dakota have voted in unison - casting their ballots for the same nominee. For 21 of these cycles (including each of the last 12 since 1968) Republicans carried the Dakotas with just three cycles going to the Democrats (1932, 1936, and 1964). This streak stands in contrast to the first few decades after statehood when North and South Dakota supported different nominees in four of the first seven cycles. North Dakota narrowly backed Populist James Weaver in 1892 while South Dakota voted for incumbent Republican Benjamin Harrison. In 1896, it was North Dakota backing GOPer William McKinley while South Dakota supported Democrat William Jennings Bryan by less than 200 votes. North Dakota voted Democratic in 1912 and 1916 supporting Woodrow Wilson while South Dakota cast its Electoral College votes for Progressive Teddy Roosevelt and Republican Charles Hughes respectively.